21 Dec Diesel Exhaust

Diesel Exhaust Safety

Diesel-powered vehicles and equipment are commonly used in construction, transportation, warehouses, maintenance facilities, and industrial operations. Diesel exhaust contains a complex mixture of gases, vapors, and fine particles that can create serious health hazards, particularly when engines are operated indoors or in poorly ventilated areas.

What Is Diesel Exhaust?

Diesel exhaust is produced when diesel fuel is burned in an engine. It contains diesel particulate matter (DPM) along with gases and vapors that may include:

• Carbon monoxide.
• Nitrogen oxides.
• Sulfur compounds.
• Hydrocarbons and other organic compounds.
• Formaldehyde and other hazardous substances.

The extremely small particles in diesel exhaust can be inhaled deeply into the lungs. Diesel engine exhaust is recognized as a human carcinogen by major occupational and public-health authorities, making long-term exposure an important workplace health concern.

Health Effects

Inhalation is the primary occupational route of exposure.

Short-term exposure to diesel exhaust may cause:

• Headache or dizziness.
• Nausea.
• Eye, nose, and throat irritation.
• Coughing or wheezing.
• Chest tightness.
• Respiratory irritation.

Repeated or long-term exposure may contribute to chronic respiratory problems and an increased risk of lung cancer. Employees with asthma or other respiratory conditions may experience worsening symptoms when exposed to diesel exhaust.

Employees experiencing symptoms they believe may be related to diesel exhaust should move to fresh air, notify their supervisor, and obtain appropriate medical attention when necessary.

Who May Be Exposed?

Workers with increased potential for exposure include:

• Construction and tunnel workers.
• Truck and bus drivers.
• Mechanics and maintenance personnel.
• Loading-dock and warehouse employees.
• Forklift and material-handling equipment operators.
• Miners and underground workers.
• Employees working around generators, compressors, pumps, or other diesel-powered equipment.
• Workers in garages, shops, enclosed structures, and other areas where diesel engines operate.

The risk increases when diesel equipment is operated indoors, underground, or in enclosed or poorly ventilated spaces.

Controlling Diesel Exhaust

Exposure should be controlled using the hierarchy of controls, with priority given to eliminating or reducing exhaust at its source.

Equipment Selection and Substitution

Where feasible:

• Use electric, battery-powered, or other lower-emission equipment instead of diesel-powered equipment.
• Select newer, lower-emission diesel engines and equipment.
• Use appropriate manufacturer-approved emission-control technology.

Alternative-fuel engines can still produce hazardous combustion products and must not be considered safe for indoor operation without adequate ventilation and exposure controls.

Ventilation

Ventilation is especially important when diesel equipment operates indoors.

• Use local exhaust ventilation to capture exhaust directly at or near the tailpipe whenever practical.
• Provide adequate general mechanical ventilation.
• Position exhaust outlets so contaminants are not drawn back into occupied work areas.
• Keep ventilation equipment properly maintained and operating whenever required.
• Never rely solely on open doors or windows when they cannot provide adequate contaminant control.
• Do not operate combustion engines in confined or enclosed spaces without evaluating atmospheric hazards and providing appropriate controls.

Safe Work Practices

Employees and supervisors can reduce diesel exhaust exposure by following these practices:

• Do not allow unnecessary engine idling.
• Shut equipment off when it is not needed.
• Follow company and site-specific idling restrictions.
• Keep workers away from exhaust outlets whenever possible.
• Do not position running equipment where exhaust can enter buildings, trailers, excavations, or other occupied areas.
• Maintain engines according to manufacturer recommendations.
• Inspect exhaust systems for leaks and damage.
• Maintain diesel particulate filters and other emission-control equipment as required.
• Report unusually smoky, strong-smelling, or poorly operating equipment.
• Remove equipment from service when mechanical problems are causing excessive emissions until appropriate repairs are completed.
• Never attempt to defeat, bypass, or remove required emission-control equipment.

Indoor and Enclosed Operations

Diesel engines operating inside buildings, garages, tunnels, excavations, or other enclosed locations require additional attention.

Remember that carbon monoxide is colorless and odorless. The absence of visible smoke or noticeable exhaust odor does not mean the atmosphere is safe.

Where exposure may be significant, the employer should evaluate atmospheric conditions and determine whether additional engineering controls, air monitoring, work-practice controls, or other protective measures are necessary.

Respirators should not be used as a substitute for feasible engineering controls. When respiratory protection is required, it must be selected and used under the company’s Respiratory Protection Program.

Remember

If you can see or smell diesel exhaust, take action—but don’t assume you’re safe just because you can’t. Minimize idling, maintain engines and emission controls, provide adequate ventilation, and keep exhaust away from workers and occupied areas.